1. Field of the Invention
An object of the invention is an aircraft provided with a ventral fairing or belly fairing. More specifically, an object of the invention is an aircraft whose belly fairing has great length. The fairing of the aircraft of the invention is formed by two independent parts. The invention can be applied in aeronautics.
It is an aim of the invention to provide a fairing capable of absorbing compression and bending forces caused by the movements of the aircraft and transmitted to the fairing, whatever the size of said fairing. More specifically, the aim of the invention therefore is to reduce the frontal loads absorbed by the fairing. It is an additional aim of the invention to diminish the total weight of an aircraft provided with a fairing.
2. Description of the Prior Art
In aeronautics, aircraft provided with a belly fairing, are known. The fairing is fixed on a lower part of the fuselage of the aircraft at the intersection of the fuselage with the wing structure. The belly fairing plugs the lower part of the fuselage. The belly fairing, which is cradle-shaped, is provided with a base and two sides, or longitudinal panels, rising laterally on either side of the fuselage. Each panel is provided with a recess capable of letting through a wing of the aircraft wing structure.
At present, the fairing is fixed to the lower part of the fuselage, on an entire periphery of said fairing. It also possible to add localized fastening devices (or fixing mechanisms) such as those described in the patent FR 2 836 890, to optimize the holding of the fairing to the fuselage. Thus, for example, an aircraft with a fairing of about 20 meters may be provided with about ten of these localized fastening devices, evenly distributed throughout a surface of the fairing. Each localized fastening device connects the fairing to an internal structure of the fuselage.
Such an approach gives good results for holding the fairing to the fuselage in small or medium-sized aircraft. A small or medium-sized aircraft is understood to mean an aircraft whose belly fairing has a length not exceeding 25 meters, i.e. 25 meters taken from the front to the rear of the aircraft, the front and rear of the aircraft being defined relative to the direction of progress of the aircraft. Indeed, in the case of such an aircraft, the dimensions of the fairing are such that said fairing is capable of absorbing the compression and bending forces to which it is subjected during movement of the aircraft.
However, there is a growing trend towards increasing the size of aircraft, especially in order to increase the quantity of load during each transport operation. The size of the associated fairing may attain sizes of more than about 30 meters. Owing to the length, certain zones of such a fairing may be subjected to major compression forces linked to the bending of the fuselage. It is difficult for these forces to be absorbed by the fairing.
To resolve this problem, a large number of localized fastening devices may be used to ensure that the fairing is properly held to the fuselage throughout the length of said fairing. However, increasing the number of localized fastening devices considerably augments the total mass of the aircraft.
The invention seeks to resolve the problems stated here above by proposing a two-part fairing. The two parts are independent of each other from a structural point of view but ensure continuity of aerodynamic shape. Each part is fixedly joined to the fuselage of the aircraft by means of a fastening of a periphery of each part to internal structures of the fairing. Advantageously, a rear end of the fairing is independent of the rest of said fairing. Indeed, a rear part of the fairing comprising the rear end is, by its size, the part of the fairing most subjected to compression and bending forces. Separating the rear part reduces the transmission of the frontal load along said rear part, from a front end to the rear end of the fairing. The number of localized fastening devices needed to hold the fairing to the fuselage is furthermore reduced, since the fairing is less subjected to forces tending to tear it away from the fairing.